The present invention relates to spray guns for spraying liquids such as paint or the like, and in particular to a spray gun assembly including a paint supply container having motor driven agitator means for automatically mixing the paint in the container.
In the spraying of paints and other suspensions by means of a spray gun assembly including a spray gun and an associated paint supply container, it is desirable to provide agitation of the paint in the supply container to prevent suspended pigments from settling to the bottom of the container and to produce optimum distribution of pigment in the vehicle. It will be obvious that in the spraying of various liquids other than paint, it is often necessary to provide for agitation in the supply container to effect proper mixing of the various components of the liquid to be sprayed.
Prior attempts to agitate paint within a supply container include the provision of movable agitator members inside of the container, whereby upon manual shaking of the container the agitator members move about within the container and produce mixing of the contents therein. However, such an expedient is subject to the disadvantage that it is not automatic, and thus repeated manual shaking of the container is required to maintain thorough mixing.
Another type of prior agitator for a paint supply container of a spray gun having a manually operable trigger mechanism is described in U.S. Pat. No. 3,412,937. As taught therein, an agitator member is disposed within the paint supply container and secured to an agitator rod which projects outwardly of the container. The rod is engageable by the spray gun trigger mechanism for actuation thereby, whereby each time an operator squeezes the trigger to produce a spray of paint, the resulting movement of the trigger automatically imparts movement to the agitator within the container to effect mixing of the paint supply. A disadvantage of such an arrangement, however, is that if the spray gun assembly is allowed to sit idle for a period of time, and unless the gun is triggered relatively frequently, pigment tends to settle in the bottom of the container.
Yet another contemplated agitator comprises a rotary impeller disposed in the paint supply container and driven by motor means. Although such agitators operate relatively continuously and maintain agitation of the paint, the mixing obtained with rotary impellers has been less than satisfactory.